I had an uncanny experience like that as a teenager with an "NPC like" character. I was walking around a small cul-de-sac, and there was an older woman standing in front of her house, completely frozen in place, just staring off into the distance blankly.
As I'm walking past she suddenly looked at me and barked out rather aggressively "Do you know what time it is?"
I checked the time on my phone and told her it. She snapped "NO! It's [completely different time]", she sounded angry as hell, I actually got a little scared.
Then she just glared at me in complete silence.
I started walking away and she just turned her head, watching me, but not saying another word.
She didn't move from the spot she was standing on.
That said I blame dementia, psychosis, drugs, or otherwise failing mental health before I'd jump to the nothing is real or everything is a simulation conclusion, but it was definitely such an uncanny feeling situation that it stuck with me to this day.
Based on what you said about viewing music as a kind of language that can be written down and understood, I actually want to suggest something maybe a little less conventional: Making music in a DAW (digital audio workstation - basically software to make music) on a computer. Depending on the keyboard you have, you may be able to plug it in and use it to control instruments in the DAW.
The reason I think you might actually enjoy getting started there is because it's a great way to dip your toes in different areas of music without much experience.
Your very first song attempt will likely have you learning about creating melodies, scales, chords, bass, effects, song structure, etc. You won't necessarily learn a LOT during that first song, but you'll learn a tiny little bit about many different musical things. And you'll get to experiment and make something fun in the process. Your first songs will probably sound a little goofy, but they'll be your very own creation - rather than just someone else's song you've learned to play.
As you make songs, you can search up tutorials on each of the things you want to learn, like "drum patterns for [genre]" or "how to make a catchy melody for [genre]", or "how to use reverb properly" or "how to structure a song", just search up things as you run into the need for them. Or even follow complete tutorials for making a song from start to finish, and then experiment and add your own spin on things.
With each song you'll get progressively better, and learn more about music, and all of these lessons can translate into learning musical instruments too. You'll get understandings of things like scales, and chords, and basic music theory. Then if you learn any instrument you can even record it and incorporate it into one of your tracks!
Just thought I'd suggest this because like you I very much view music as like a language to learn, and I struggled to learn various instruments with little initial success - but then found myself drawn to making music on my computer and have fallen in love with it!